Table 4.

Maternal health complications by treatment arm: the Effects of Aspirin in Gestation and Reproduction trial.

Maternal health complication*	Low-dose aspirin N=615 n (%)	Placebo N=613 n (%)	RD	95% CI	P
Death	0 (0)	0 (0)	NA	NA	NA
Preterm contractions	29 (5)	36 (6)	−1.2	−3.7 – 1.3	0.38
Bleeding
Vaginal bleeding†	138 (22)	104 (17)	5.5	1.0 – 9.9	0.02
Subchorionic hemorrhage	48 (8)	38 (6)	1.6	−1.2 – 4.5	0.37
Vaginal‡ bleeding or subchorionic hemorrhage	157 (26)	122 (20)	6.2	1.4 – 11.0	0.01
Epistaxis	7 (1)	1 (0)	1.0	0.1 – 1.9	0.07
Emesis	299 (49)	279 (46)	3.1	−2.5 – 8.7	0.28
Kidney stones	11 (2)	9 (1)	0.3	−1.1 – 1.7	0.82
Premature separation of placenta	7 (1)	5 (1)	0.3	−0.8 – 1.4	0.77
Postpartum hemorrhage	4 (1)	4 (1)	0.0	−0.9 – 0.9	1.00

Abbreviation: RD, risk difference; CI, confidence interval; NA, not applicable

P-value calculated using Fisher’s exact test. P<0.05 bolded.

^*Health complications were compiled for each participant using information collected from case report forms, interviews conducted during pregnancy and postpartum, and chart abstractions of prenatal visits, ultrasounds, pregnancy loss, emergency care and delivery medical records. Adverse events include both self-reported and medically documented conditions.

^†Vaginal bleeding included reports of unusual vaginal bleeding when not pregnant, reports of vaginal bleeding after becoming pregnant and complaints of vaginal bleeding at the time of delivery.

^‡Vaginal bleeding only included reports of vaginal bleeding after becoming pregnant and complaints of vaginal bleeding at the time of delivery. P-value calculated using Chi-squared test. Inverse probability of conception weights were applied to control for selection bias introduced by stratifying on pregnancy status.